c++ - C++ 中的二维整数数组，每行元素数量为奇数

Question

该数组的行数和列数由用户指定，但行数不相同(数组不均匀)，并且用户将通过输入元素来填充数组。

这是我编写的代码，但是当我尝试获取用户的输入时，代码在获取一些输入后崩溃了。请您帮助我纠正我的代码并指出我的缺陷。谢谢。

#include <iostream>
//2d array
using namespace std;

int main()
{
    int row;
    int col_x;
    cout << "Enter the row number:" << endl;
    cin >> row;
    //cout<<"Enter the column number:"<<endl;
    //cin>>col;
    int **a = new int *[row];
    for (int r = 0; r < row; r++)
    {
        cout << "Enter the column no.of array " << r << endl;
        cin >> col_x;
        a[r] = new int[col_x];

        cout << "Enter the elements in the array:" << endl;
        for (int i = 0; i < row; i++)
        {
            for (int j = 0; j < col_x; j++)
            {
                cin >> a[i][j];
            }
        }
        cout << "The elements in the array:" << endl;
        for (int i = 0; i < row; i++)
        {
            for (int j = 0; j < col_x; j++)
            {
                cout << a[i][j] << " ";
            }
            cout << endl;
        }
    }

    delete[] a;
    a = NULL;

    return 0;
}

Answer 1

有一个额外的 for 循环。另外，您必须存储每行的大小。并对二维数组进行正确的释放。

#include <iostream>
//2d array
using namespace std;

int main()
{
    int row;
    cout<<"Enter the row number:"<<endl;
    cin>>row;
    int **a=new int *[row];
    int *col_x = new int [row];

    for(int r=0;r<row;r++){
        cout<<"Enter the column no.of array "<<r<<endl;
        cin>>col_x[r];
        a[r]=new int[col_x[r]];

        cout<<"Enter the elements in the array:"<<endl;

        for(int j=0;j<col_x[r];j++){
            cin>>a[r][j];
        }
    }

    cout<<"The elements in the array:"<<endl;
     for(int i=0;i<row;i++){
        for(int j=0;j<col_x[i];j++){
            cout<<a[i][j]<<" ";
        }
        cout<<endl;
    }

    for (int i=0; i<row; ++i)
        delete[] a[i];
    delete []a;
    delete []col_x;
    return 0;
}